80vetteL82

I put down 13k. Makes your payments much nicer. You can never put down too much as long as you have it to put down. Itll just lessen the amount of interest youre gonna pay.

This is definitely good news, Im subscribed and keeping my fingers crossed that it comes out soon and the price is decent!!

Cyrusthevirus

iTrader: (7)

I bought my outright, walkin in with the check!

Smallywood

They gave me mine for free...

lecznar1

haha lol i got mine out of one of those claw/crane lookin machine things

JPizzle

Well, I stole mine. So...

Smallywood

Actually, I just realized they paid me to walkin out the door with it! I am uber kool ike that!

80vetteL82

haha damn...I wish I was that lucky.

08inBama

GM sent me one to test drive for 5 years at $475 a month

80vetteL82

Im still pretty new to turbos....but it seems like these cars have virtually no turbo-lag stock. Maybe its just me, but it seems like whenever I increase the throttle even slightly the boost is right there with me.

thehov

i agree with ya......... I've owned 5 turbocharged cars and the Cobalt doesnt show any real turbo lag.... My 94 TT Supra even with two turbos showed lots of lag and I dont even want to talk about my 02 WRX with an APS SR55 turbo, now thats lag.......

Cobalt............ No lag..........

08inBama

yeah there isn't much lag, BUT its still much quick brake boosting

the lag is nothing terrible though, in a lot of cars without brake boosting, from a roll.....they are just absolutely terrible and it doesn't matter what rpm you are at, it takes forever for the turbo to spool

the cobalt will still put up a decent fight even without a brake boost

SS4EVER

Yeah that's the beauty of the Borg Warner twin scroll KDO4 turbo that's in the LNF, it's smaller so it spools up quicker, only downside is the lower top end...

80vetteL82

like I said Im kinda new to turbos so...what exactly is brake boosting. I could probably guess, but I figured I might as well ask.

lecznar1

pretty much just holding up the e-brake and letting it down when you launch giving it a lil gas and letting out the clutch just enough to kind of "stage" the car if you will... some people do it differently but that's the way I do it

08inBama

no, brake boosting is while rolling, slightly pressing the brake, while giving it throttle, thus maintaining your speed(say a 30 roll) and building boost, so that when you go WOT, you already have your turbo spooled

its essential in racing cars from a roll that will actually put up a fight

the thing is in our cars its not night and day of a difference, its noticeable(and much quicker building boost) but in cars like say an Evo or a WRX, if you DON'T brake boost, you are going to be getting walked by cars like a 3.5L Nissan Maxima(from a roll), lol

for example:

http://www.youtube.com/watch?v=iR8Oj4KykJQ

http://www.youtube.com/watch?v=nH_5n...eature=related

the second video is more informal

lecznar1

another way to do it... nice post man!!

blackbird

The term is primarily applicable to automatic transmission cars but it can be performed on some manual trans cars. Basically in an automatic car it's holding the brake pedal down while getting on the gas in order to build boost prior to taking off. If you were to just to floor the gas and bounce the engine off redline with a car in neutral you wouldn't build any boost because there's no load on the engine and it doesn't take much fuel just to spin the engine internals. And if you're not burning a large volume of air and fuel like you do when the car is under load (such as when the car is accelerating) there isn't enough exhaust gasses to spin the turbo to build boost.

When you brake boost a turbocharged automatic trans car you're not just spinning up a free revving engine in neutral but instead are trying to overpower the brakes on the drive wheels. Brakes are almost always stronger than the engine power so the engine ends up burning a lot of air and fuel as the engine is now under a heavy load trying to overpower them. That allows higher exhaust gas volume to drive the turbo and allow it to build boost without the car moving.

Downside to doing that is something has to "give" and in an automatic trans that would be the torque converter. All the engine's power instead of going to move the car is being transferred and placed on the torque converter if you're trying to do it from a stop and it's not much better if you do it while the car is moving. The torque converter (which is a fluid coupling device) has to slip excessively which creates a ton of heat in the trans fluid and heat is the number one killer of automatic transmissions. An occasional quick jab of the gas while on the brake might not be too bad but a heavily modified car putting down big torque numbers and extended boost braking will kill a trans very fast, even many that have internal upgrades and cooling modifications.

On a manual transmission car like our Cobalts you don't have a torque converter and instead have a clutch. In order to place a load on the engine you'd have to keep the car from moving while stopped. If you tried to use the parking brake it may hold the car from moving forward but if you let out the clutch while on the gas the front tires are going to light up and as soon as that happens there isn't that much load and therefore not much boost. You could also hold the brake down with the heal or left side of your right foot while giving the car some gas with that same foot while using your left foot to operate the clutch. Just like the torque converter, when you're restricting the drive wheel from moving (with the brakes), something has to give and that will be the clutch.

In the SS Turbo that's probably not a great idea. Do it wrong or even if you do it right it will build up a ton of heat which can cause the organic clutch lining material to glaze over and slip, permanently ruining the holding force of the clutch. It appears the stock clutch can take quite a bit of hard launches and the stock torque capacity of the engine but slip it too much and overheat it and that all goes out the window.

Now while you're on the move and the clutch is fully engaged and locking the flywheel to the input shaft on the trans you could slightly get on the brake pedal while continuing to give the car some gas. That will place more load on the engine as it will try to overpower the brakes and therefore produce a higher volume of exhaust flow to drive the turbo. This is still pretty hard on the driveline and if you have a weak clutch or do it too hard it may slip and effectively ruin any clamping force the clutch had left to offer.

In moderation while on the move and the clutch fully engaged it might be okay if you're careful but I personally wouldn't do it to my car. That and when you're already on the move the transient boost response of the stock turbo is great as-is on the SS Turbo. On another car with a giant aftermarket turbo it could definitely help get it spooled quicker but we really don't have that problem stock while on the move.

80vetteL82

alright cool, thats what I was thinking. Thanks for the great explanation though.

SportredSS

I would not believe him just because he works at a dlr. Just like Bush saying there are WMOD in IRAQ, when in fact there never was. Do research before believing everthing someone says, this why Bush got re-elected, because DUMB Americans believed everything that rolled off his lying tongue.

Do your homework first, especially today in this F**K'ed up country of ours .

I have relatives that have been in GM Engineering for 20 years and they say no such perfrormace package upgrades will be offered in the immediate future (next 3 years) till GM is back on terra'firma from a financial perspective.

MARIN007

Can you then explain why GM hardware and calibration numbers have been leeked?

08inBama

you can't "brake boost" a manual car off the line without using the hand brake, and in a fwd car, unless you are running full blown slicks, you are wasting your time, as you will be turning 2.4 second or worse 60's...

krispy

I was highly skeptical too, but there is good evidence this is planned to become a reality.

Gyrocon

Man I hope so! that kit will be sweet if they actually produce it!

MARIN007

I think someone said that SEMA is the most likely event that would announce this tune. If this is true, on November 4th there are going to be a lot of eager SS/TC owners.

TrevMo

It was in some emissions approvals for some government agency in CA. Check the other pages...there is a link to the PDF...

I said that it would make sense if they were going to announce it there...pure speculation though...I have no idea when this will be officially announced...